Unit expansion furnace walls



Dec. 31, 1957 o'. NYGAARD UNIT EXPANSION FURNACE WALLS 2 Sheets-Sheet 2 Filed Aug. 5. 1953 JNVENTOR.

United States UNIT EXPANSION FURNACE WALLS Oscar Nygaard, Saugus, Mass., assigner to Bernitz Furnace Appliance Company, Boston, Mass., a corporation of Massachusetts Application August 5, 1953, Serial No. 372,519

11 Claims. (Cl. 11G- 1) This invention relates to furnace walls, and more particularly to the improvement of the structural parts of furnace Wall linings directly exposed to the intense internal heat of the furnace.

The invention pertains further, to the improvement of the type of fire side linings of furnace walls that is constructed to form an independent inner section, adapted to be spaced if desired from an outer wall section, and which inner section is normally made up of suitably designed building units to accommodate the characteristics of the particular refractory materials used.

One object of my rinvention is to provide a structure particularly adapted for having most, or possibly all, of the parts thereof, including their supports, made of silicon carbide refractory materials.

Another object is to provide greater stability of alignment between the various lining members along with means to facilitate erection and thus reduce the labor cost of installation and repairs.

Still another object contemplates the formation of the shapesof the lining and their assembly so as to make the lining tight and leakproof, and to so strengthen the supporting and the supported lining members that breakage and premature failure will be prevented.

My U. S. Patent No. 1,806,113 is pertinent in the consideration of this patent application, in that it describes specifically the type of furnace wall lining my present invention seeks to improve by the elimination of certain undesirable structural features shown therein, and to effect such other additional advantages as will become apparent from the following detailed description of my present invention, when read in conjunction with the accompanying drawings. Novel features of the invention will be further pointed out in the appended claims.

ln the drawings:

Fig. 1 is a front elevational View of assembled lining members forming the tire face body of the wall, and showing a portion of a backing up wall with built in lining suppe t Fig. 2 is a si of Fig. 1.

Fig. 3 is a cross sectional plan view taken on line 3*-3 of Fig. l.

Fig. 4 is a perspective rear view of a wall section sh-owing the interlocking relationship of the inner or re face lining members with the supporting members imbedded in, and anchored to, the backing up outer wall.

Fig. 5 is a cross sectional side View of a wall with lining members arranged and supported to form a re face surface positioned at `an incline from the vertical, yshowing a modified type of supporting member and anchoring means, also air supply inlets for horizontal air flow, the section being taken at or about the center line of a lining unit and its supporting member.

Fig. 6 is an elevational view in perspective showing the assembled relationship of various lining members and their supports.

Figs. 7, 9, l0, l1, 12, 13, and 14 are isometric drawe croos sectional view taken on line 2--2 ice ings showing the preferred form of the shapes that make up the lining.

Fig. 8 is a side section taken on line 8 of Fig. 7.

Fig. l5 is an isometric of a modification of the lining member shown in Fig. 9.

Fig. 16 is a fractional side section taken at about the center line of a vertical tier of an inner lining section of a modified construction.

Fig. 17 is a side cross section showing a form of supporting member such as may be used when made of tire clay materials.

Like parts have been numbered alike in all the drawings.

ln Figs. 1, 2, and 3 it will be noted that the construction there shown comprises an inner or front Wall section A and an outer or rear wall section B. The face of the front section A is exposed to the re and forms the re side lining of the wall. These wall sections are of distinctly different construction, and substantially separated from each other by an air space C, also shown in Figs. 4, 5, 16, and 17. The outer wall section B may also be termed the permanent wall section, since that section is not directly exposed to the tire; hence, has much greater wearability than the inner section A.

The wall section B may be tted with air pipes or ducts d-d for venting the air space C as indicated by the arrows in Fig. 2, or the air space may be partially or fully vented by providing suitable apertures 1a and 2a, through the re face body of the lining blocks 1 and 2, as shown in Figs. l, 4, 7, and 8, but while it is preferable to have air circulation for cooling the liningy section A in most instances, it may however, be dispensed with to advantage in others to simplify the installation and reduce cost, since the proper functioning of the inner fire side lining is not dependent upon air circulation. While I have conveniently shown the permanent outer wall built of ire brick, any other structure of a substantially permarient nature for backing up and supporting the lire side lining will serve equally well.

As best seen in Fig. l, the fire side lining A is erected from horizontally and vertically aligned panel-like structures separated from each other laterally by suitable clearances e and e-l, `and vertically by clearances f and f-1, to allow for independent and adequate expansion between the panels in all directions, and to give room for any permanent growth that may occur in the building units after some length of service. The panels overlap each other at some distance to the rear of the fire face of the lining, with the overlapping portions only in sliding engagement and contact with each other. See Fig. 3. This construction permits the panel units yof the lining to freely expand or grow independently of each other and of the permanent backing up Wall, without the loss of continuity and alignment between the panels or panel members. Since all of the panels are afforded unhindered automatic inter-adjustment, no accumulative expansion or marginal growth of the lining A can possibly occur, and it can thus 'be built to protect any size area of a furnace wall to make the main body of the wall more permanent. Hence, the height and width of the lining is a matter of choice or selection.

The panels of the tire side lining are principally constructed alike, but diifer from each other in that alternate panels in a lateral direction have side projections at the rear away from the re side, forming flanges that overlap a body portion of the adjacent alternate panels. All panels have a rear bottom flange except this flange may be eliminated in the base panel blocks 1b and 2b as shown in Fig. 2. In all other respects the blocks 1b and 2b are identical to blocks 1 and 2 respectively.

1n Figs. 7 and 8 the panel block or member 1 is shown to have a main. body '7 facing the tire, and having rearward extensions 8 8 terminating at their lower extremity to form portions of a flange 9 joining the extensions 8-8 together and extending downward from the rear side of the body 7, parallel thereto and being integral therewith. The upper surface 10 of the flange between the extensions 8 8 is preferably slanted upward toward the body 7 to provide strength with a minimum amount of material and to provide smoothness of air flow within the assembled lining. A gradual reduction in the rearward dimension of the extensions 8 8 is accomplished by the downwardly and inwardly sloping surfaces 11 11, which are of importance for several reasons: (l) A considerable saving of a very costly material is effected. (2) Maximum structural strength is maintained in the overlaying portion of the extensions, which is very important, because a failure, caused by even a minor part of the overlaying part breaking off, might allow the whole panel unit to fall away from the Wall, and thus expose the outer permanent wall to the damaging intense heat of the furnace. Also, a large amount of excess air would escape to the furnace interior causing loss of operating etliciency as well as causing a greatly reduced, and possibly the entire stoppage of, air circulation over a large portion of the lining, which could result in damage to other'lining members. (3) The upward how of cooling air is guided to an even and smooth current instead of being opposed and greatly retarded by eddy currents caused by the air striking squarely upon surfaces jutting directly out into the air stream; thus an even cooling is obtained over all contacting surfaces.`

The portion of extensions 8 8 above, or overlaying, the surfaces 11 11 are of substantially thicker cross section, as will be seen by comparing the width of the upper surfaces 12-12 with the surfaces 11 11. This produces integral portions 13 offset toward the center of the block. The offset portions 13 have each in their bottom surface an upwardly extending recess or depression 14 bordering the block body 7, and bounded at the rear by what may be termed a retaining lug 15, and being a part of the portion 13.

The panel block 2 Fig. 9 has a main body 16 of the same thickness and height, but being of somewhat lesser width than the main body 7 of the alternating panel block 1. Like block 1, block 2 has two rearward extensions of exactly similar construction as the extensions 8 8, Fig. 7, with the exception that side flanges 17 17 have been incorporated, and further explanation will presently be given. For the foregoing reason, and for the sake of simplicity and brevity, the numeral 8 has been applied also to the rearward extensions of block 2 Fig. 9. All other numerals, together with the detailed description pertaining to the various parts of these extensions, have been purposely left out from this application, as it would only be a duplication of the description given for these parts of block 1 Fig. 7. Reference may also be had to side section Fig. 8 which is typical for both blocks 1 and 2.

In Fig. 9 it will be seen that the side flanges 17 17, which might also be termed rear side flanges, are really sidewise projections from the rearward extensions 8 8 terminating in line with the lower edge of the rear bottom flange 18, and being of the same thickness line up to provide a continuous smooth front surface 19, that will fit snugly to the rear surfaces 20-20 of the block body 7 Fig. 7 for sliding engagement when assembled to form a wall facing or lining as clearly shown in Figs. 3 and 4, and which also show that suitable clearances are provided at the extreme edges of the flanges 17 17 to accommodate such sliding engagement.

Panel blocks 1, 2, 1b, and 2b are supported in their relative positions in the lining by the supporting member Fig. 12, there shown in the preferred form.

The main body portion 21 is of rectangular form and of a size such that it can be readily laid up with and bonded to the brick of the permanent outer wall.. The outer :end of the body part 21, adapted to be bonded and, when required, also interlocked or mechanically anchored to the outer wall structure, is provided with a slot 22 to receive a metallic anchor 23 of the type commonly used in brickwork, as illustrated in Fig. 4. Other types of anchors may be used to advantage for mechanically and firmly locking the supporting member 5 to the outer wall, such as shown for example, in Fig. 5, the detailed description of which will appear later herein. Such metallic anchors are a necessity when the outer wall is built of a comparatively thin cross section, and the provision of means within the supports 5 to co-act with and contain such anchors is a distinct improvement over any prior construction of the generic nature of this invention.

At the forward or inner end of the support 5, two upstanding laterally spaced supporting lugs 24-24 are located and integrally held in their spaced relation to one another by the centrally elevated body portion 25, which extends outward from the inner end of the support 5 a distance sufficient to meet and contact with the inner surface of the outer wall, and thus will provide means for spacing to a perfect alignment the fire side lining members from the outer wall the amount needed to allow the the required width of the interior space C for passing a precalculated quantity of cooling air at a moderate velocity therethrough.

To that end, provision is made in the mold for fabricating the support 5 so that a selected length of the body elevation 25 will `be had, such, for example, as shown by the dot and dash line extension of the elevated body rib 25. Besides serving to space the supporting lugs 24-24 and greatly strengthen these vital parts by the integral relationship between them, which is very important from a wearability or service life standpoint, the body rib 25 provides much added strength to the projected overhanging end of the support 5, and also functions as a spacing lug between the lire side lining and the outer wall. The channel 26 in the inner end of supports 5, to form a passageway for air circulation, is of importance in providing a free and unobstructed air ow over a maximum area of the lining members.

The upright supporting lugs 24-24, have each a at upper surface 27 positioned at a slightly acute or oblique angle to the inner end of the support 5. The angularity and extent of these surfaces are equal to, and correspond to, the angle formed with the body 7 by the surfaces 28, Figs. 7 and 8. Thus it will be understood that the lugs 24-24 Fig. 12 are made to t snugly into the recesses 14 Figs. 7 and 8, forming thereby complementary obliquely disposed supporting surfaces, whereby members of the furnace lining will be firmly supported in tight interlocked relationship with the supports incorporated in an outer furnace wall section.

It should be realized, however, that manufacturing tolerances must be allowed in the making of the interlocked parts, which could result in a slightly looser lit than desired, and the object in making the surfaces 27 obliquely situated is to insure a firm contact of the lining members with the inner end surface of the support members. Any looseness then noted can be corrected, and the desired rigidity obtained, by applying a little lireclay to the rear side of the lugs 24. Not only are the lining members held rigid against the lugs 24 in a direction inward and outward of the wall, but the spacing part 2S between the lugs, and the opposing sides of the extensions 8 of the panel blocks, between which the lugs 24 are fitted snugly, will also positively prevent movement sidewise of the lining members.

Thus maintenance of the side clearances e between them is assured, while the .inward rigidity prevents movement of the lining members out of vertical alignment.

As clearly shown in the drawings, the outer more permanent wall is studded with projections 5 at evenly spaced intervals in a manner to align and arrange the meeting of the projections with the lining members supported thereon at or about the center of the supported members, to form a well balanced construction with the center of gravity for each supported member at or near the center of the inner end 24 of a projected support 5.

A very severe objection to the constructions shown in my prior Patent 1,806,113 previously referred to herein, and w-hich has contributed materially to the sales resistance to this otherwise fundamentally valuable contribution to this old art, is the instability of the completed lining.

As there shown, the panel members 14 and 16 corresponding to 1 and 2 in my present application, are hung and supported in their operative position by two widely separated overhanging single lugs, with the right hand lug of one member and the left hand lug of an alternating member rest-ing on the same support with no Aprovision for either lateral, inward or outward containment-s to obtain rigidity of position. Even a light blow of a s'lice bar or other cleaning tool commonly used in furnace operation, accidentally or otherwise striking the lire face at almost any place, can distort and disaflign the various members of the lining with practically no chance of automatically resuming their relative position, to prevent air leaks and to accommodate expansion to eliminate crushl ing and spelling.

The overhung lugs referred to are structurally very weak, being without integral reinforcing sides extending across the recess fitting over the rounded supporting edge of the supporting brick of the permanent outer wall. Hence, any extra strain caused either by a blow of a cleaning tool or from the weight of adhering Kclinkers can easily result in a cracking olf of the retaining hook of the lug and let the block fall into the furnace.

In my present invention all these and other disadvantages are overcome as will be clear from the descriptions rendered. For example, in my present invention a large area of the front Ibody of the lining blocks has been exposed to the benecial cooling air and much costly material has thus been saved. The cooling surface of the lining blocks of my prior patent lies further outward in the wall from the lire face, since they included with the body portion also the rear flanges, making the blocks thicker, more costly, and less suitable for eilicient cooling.

Seated on top of the lining block 1 and 2, previously described are the iil'ler bl-ocks or members 3 and 4, so called because of their position in the lining to till the gap between the vertically spaced lining blocks 1 and 2 or 1b and 2b. The structural details of block 3 is shown in Fig. l and those of block 4 in Fig. 11.

Both of the panel members 3 and 4 are in seated interlocking engagement with lining members 1 and 2 respectively. The interlocking engagement may be accomplished by a tongue and groove construction as shown at 29 Fig. 2, or by any other equally or more effective known interlocking arrangement.

It will be understood from an inspection of Figs. l, 2, 6, l0, and 11 that all lateral dimensions of the filler blocks 3 and 4 are exactly the same as for the lining or panel blocks 1 and 2 or 1b and 2b, upon which they are seated. Thu-s they match and line up to complete the respective panels of which they are a part, to provide clearances or expansion joints at their sides of equal Width, and in perfect alignment, with those had between the blocks 1 and 2 or 1b `and 2b.

When viewing Figs. l0 and l1 it will become apparent that, by a movement sidewise toward each other, the rear portion 30 of Fig. l() will meet the rear portion 31 of equal height Fig. 1l, lto produce a lapped construction when assembled similar to that obtained between the members 1 and 2. Likewise the side sealing lugs 32-32 of liller block 4 will enter the corner recesses 3.3-3.3 of filler block 3 to promote overlapping relationship.

The vertical clearances between the panels represented by the horizontal expansion joints f and P1, Figs. 1 and 2, are made larger than the lateral clearances or vertical joints e and eel, to allow the liller blocks 3 and 4 to be lifted clear of their interl-ocking means with the panel blocks 1 and 2. The vertical clearances f are preferably lled with a high temperature resistant resilient packing material to insure tightness of the lining along these joints, Whereas the clearances f1 are not to be so packed. I prefer to also make the top surface 34 of the members 3 and 4 at a moderate downward and rearward angle with respect to the lire face of the lining, in order to better seal and lock the packing in place. An upper portion of the lire face of the members 3 and 4 is preferably tilted upward a-nd outward as shown at g Figs. 6, 10, and l1, to provide an undercut construction in rela-tion to the lire face plane of the panel members 1 and 2, and thfus prevent slag from flowing into the expansion joints f therebetween.

In Fig. 6, the lug 32 of ller block 4 is shown to effectively seal off the comparatively large vertical cle-arance f-l from the narrower lateral clearance e which leads to the furnace interior. This lug 32 then, together with the overlapping feature of the recess 33 in the filler block 3, provides a means for positively preventing leakage to the furnace interior from the air space C through the clearance e of the lining.

A tight cover for the air space C is provided by the topping blocks 6, Fig. 13. The cover block 6 is preferably made of rectangular form and of such proportion that contact with the outer permanent wall section will be made. Lengthwise of the cover blocks 6, the end-toend dimension is such that a clearance e-2 will be had and located on top of one of the extensions 8 of each alternating lining block 1, 2, or 1b and 2b, whereon the cover blocks 6 are seated in removably interlocking relationship. To insure the desired lateral disposition of the covers 6, a lug 35 is so positioned on the under side thereof that it will project downward into the space between the extensions 8 8 only when the ends v36-36 are located overlaying the extensions 8. Since the clearances e-2 are thus located on top of the surface 12 0f the extensions 8 and the rear surface of the cover block 6 is making contact with members of the outer wall to seal olf the air space at that point, no air leakage can occur to the furnace interior from the air space C through the clearances e-Z.

A vertical clearance f-2, preferably lilled with packing material, the same as for clearances gf, is shown between the covers 6 and the overhanging portion of the permanent wall Figs. l, 2, and 5. This clearance is of a height which will allow the lifting of the covers 6 to clear the interlocking tongue 37 and the lug 35 from the elining blocks whereon they are seated and thus allow removal from the lining without disturbing any adjacent part of the permanent Wall structure.

My present invention also contemplates the use of special marginal bricks 7 and 7-1 Fig. 14, of high heat resistant refractory material, preferably of silicon carbide, brick 741 being a little shorter than the bricks 7, but otherwise the same. A notched-out portion at the rear of the brick provides a front or lire side flange 38 having a thickness equal to the body 7 Fig. 7, and will therefore line up with the fire face of the lining when stacked in overlapping relation with lining members 2, 2b, and 4 as shown in Figs. l and 3. As will be seen, the marginal bricks 7 and 7-1 match up and break joints with the {legular fire brick of the adjacent wall to make a proper ond.

These special high heat resistant marginal bricks are important in that they provide protection for the narrow edge of the marginal panels of the lining, and carry out the air tight overlapping feature.

In some installations I may find it advantageous to employ lining members of the same general characteristics as those described herein, but having the extensions 8 8 made in one piece to form extension 8a Fig. 15. Although the extensions 8-8 are designed for great strength, there may be instances where even a stronger supporting structure would be desirable, of the type shown at 8u. For example, the top row of lining members may be used for supporting some courses of brick on top of them to fill in a space or to reach a fixed height of fire side lining to be made of super refractory material. Another feature in connection therewith is that the top surface 12a of Fig. 15 would not be cut up by the sep* aration of extensions 88; hence, the expansion joint e-Z can be located anywhere on the surface 12a, and standard brick could be used for closing the air space C, as no special cover blocks 6 would be necessary.

When a fixed lining height is to be made that can not be completed with the vertically arranged lining members as preferred and described herein, an arrangement including an additional separate interlocking intermediate filler block 38 Fig. 16 may be used to heighten the structure of one or more panels as desired, these intermediate filler blocks being of the overlapping type generic to the regular lining members described.

In Fig. 17 is shown a type of lining support 39, which, while retaining main structural characteristics of the support previously described, has been modified to make it more suitable for fabrication from common fireclay refractory materials of lesser strength than the silicon carbide refractory of support 5. Since the support 39 has to be made very much thicker to provide sufficient supporting strength, a lateral groove or notch 40 has been made in its inner or forward end to permit air flow in a horizontal direction, as well as the vertical direction made possible in the support 5 Fig. 12.

In furnace construction it frequently becomes necessary to offset a part of a wall as illustrated in Fig. 5. This can readily be accomplished by the construction there shown, utilizing the regular lining members previously described herein, with the exception that, instead of the supports 5 used for a vertical wall, a modified support 41 will be required, which will have at least a portion of the inner or forward end forming the desired angle of the offset lining section as shown at 42, but the interlocking of the lugs 24 with the panel lining members is seen to be the same as for the support 5.

Overlaying the packed expansion joint f-Z of the vertical lining section, I might use a special shape 43 having the fire side end portion thereof made to agree with the angularity of the offset wall lining. When a comparatively wide air space C as shown is to be used, I prefer to support and further anchor the projected members 41 by the inclusion in the permanent outer wall of the anchor plate 44, which is made long enough to overhang the brickwork of the outer wall section as shown, and thus materially help support the projected end of the refractory support 41. The overhanging portion of the anchor plate 44 may be provided with a corrugated or finned surface on the under side 4S to enhance the air cooling of the plate for safer operation. The upper surface of the plate 44 has an upstanding transverse rib or lug 46 fitting into a corresponding recess in the support 41 for interlocking one with the other. At the outer end the anchor plate is secured to an outer wall member 46 by depending lug 47 and bolt 48. When lateral fiow of the cooling air is desired, air pipes d-l may be installed as shown connected to the air space C.

The details of construction, and some of the advantages of the improvements made in accordance with this invention, have been pointed out in the preceding pages, but I want to further emphasize a few of the more important novel features of the invention, because of their importance in offering practical solutions to a number of structural drawbacks found in my prior Patent 1,866,113 referred to herein, to the end that the basic principle of that patent can be utilized in a practical manner and thus 8 t promote further economy and savings in power plant operation.

One such improvement, and perhaps the most important one, resides in the marmer in which the individual lining members are fixedly supported in relation to each other, and to the permanent outer wall structure, at approximately the center of the overlapping panel units, which definitely obviates any positional variation between the built in supports of the outer wall and the lining members, and which excludes any possibility of the lining members becoming disarranged out of positive leakproof contact and alignment with each other, yet permitting lateral expansion or growth of the lining members to take place unhindered in all directions from the approximately centrally fixed supporting means.

Another very important improvement made is accomplished by the reinforcement of the cooperatively engaged supporting lugs on both the built in lining supports or studs of the outer permanent wall and the supporting lugs on the panel or plate-like lining blocks as described herein which materially strengthen these vital parts. Also the spacing means incorporated in the supporting studs of the permanent wall save considerable erection time and add further rigidity and strength.

The sealing means shown provided herein for the elimination of air leaks at specific points through the lining are, of course, very important in doing away with a highly undesirable feature. The special sealing means provided by recesses 33 and lugs 32 of Figs. l0 and l1, the sealing arrangement at the top of the lining by the cover blocks 6, and the rabbeted ends of the marginal bricks 7, are all improvements that will insure a parctical and economical long life construction.

Having first built the outer wall to provide a recess of the proper depth and lateral dimensions for receiving the inner fire side lining, and having studded the inner surface of the recess with the built in supports 5 in proper spaced relation to each other, the lining members 1 and 2 or 1b and 2b can now quickly be hung upon the supports 5 from which they can only be dislodged by a straight upward lifting movement sufi'icient to clear the interlocking supporting lugs of the supports. The rear fiange blocks 2 are usually hung upon alternating supports in a selected panel course first, followed by the placing on their respective supports alternating blocks 1. The filler blocks 3 and 4 can then be seated upon their respective panel blocks 1 and 2 to complete the course. However, since each panel of two or more members is entirely independent of each other, the assembly of the lining can commence at any place within the lining area, or at several places at once to expedite the completion of the lining. This is a great advantage over other types of fire side linings, which have to be cement bonded and erected from the bottom upward, particularly when quick repair is urgent.

Having thus described my invention, what I desire to claim as new is:

1. A furnace wall comprising an outer main body section having an evenly recessed area in its inner side defined in part by a recessed surface, receiving therein a high heat resistant lining section facing the furnace interior, said lining being assembled from lining units which when assembled forms independent laterally and vertically aligned panels of relatively thin plate-like cross section, separated from one another by offset slip-type expansion joints which are open at the laterally opposed sides of each panel, the upper and lower joints being packed with a resilient high temperature resistant material, the latter joints increasing in thickness from their inner toward their outer sides for retaining the packing therein; the upper portion of the inner side of each panel being tapered upwardly and outwardly to provide an undercut construction at the top of each vertically succeeding panel units, each said units having on their outer side integral means for sustaining the unit rigidly on its suspenpdv sion support to prevent any lateral movement thereon and any outward or inward movement of said unit out. of alignment with the general inner plane of the lining; said outer Wall section having at spaced intervals withln its recessed area built in fixed refractory lining supports having means intermediate their inner and outer ends for anchorage in said body section, said lining supports overhanging said recessed surface and having at one side of the overhung portion an integral lug projection in contact with said recessed wall surface for spacing to an equal distance their inner ends therefrom, each said support having at its inner end an elevated portion constructed to form a seating surface whereupon a lining unit is removably and replaceably suspended and interlocked to a rigid position thereon, there being one said supporting member to each lining unit, and each said lining unit being supported at a fixed point located at its approximate center to provide freedom of expansion in all directions.

2. A structure in accordance with claim 1 and; wherein each lining unit comprises at least two vertically associated and interlocked members, the lowermost member having two integral ribs laterally spaced from one another and extending outward from the main re face body thereof, said ribs being reduced in thickness a distance downward from their top to form laterally opposed overhanging portions, which lower edge is formed to embrace and rigidly interlock with one of said refractory supports of the outer body section.

3. A structure in accordance with claim 1 and; said lining section comprising laterally adjacent pairs of refractory plate-like lining units, each having a pair of laterally spaced integral suspension ribs on their outer side, said pair of ribs having in their opposing side cooperative means for supporting each said unit in a suspended upright position on one of the fixed supports of said outer main body section, and said ribs also serving to hold said lining units in a laterally shiftless suspended position upon said fixed supports.

4. A high heat resistant lining for furnace walls erected in a suspended position thereon and in spaced relation therewith to form an internal air space therebetween for cooling the lining, said lining comprising a series of laterally and vertically aligned rows of independently supported units, each unit being composed of at least two vertically associated and interlocked members forming a vertically elongated panel structure, each panel being spaced apart from adjacent laterally and vertically positioned panels, the lowermost member of said unit being suspended in a hanging position by integral rib extensions on the outer side of said member upon seating means at the inner end of a fixed lining support incorporated in the furnace wall and overhanging the inner side thereof, said support having means at its outer end for mechanical anchorage in said wall and having its overhung portion reinforced by ribbed construction which also serves as means for equdistant spacing of the panel units from the inner side of the furnace wall; each said lowermost member having a pair of vertical reinforcing ribs in the outer side laterally spaced equdistant from the vertical center line of said member, and each of said ribs having an upper offset portion in opposed sides, the under side of which is formed to lit over and seat upon said seating means of the fixed lining support to a rigid position thereon, while the opposed sides of the ribs below said offset co-act to hold said panel unit laterally shiftless upon said lining support.

5. An inner furnace lining according to claim 4, and: a row of topping bricks covering said lining at its upper extremity and sealing over said air space at the outer side of said lining, each said topping brick having a lug in their under side extending downward between said pair of reinforcing ribs and serving to lock said topping bricks securely to the lining, and said lug being so positioned with respect to one end thereof that opposing ends of adjoining topping bricks will overlie one of said ribs of said lining member.

6. A furnace wall having an inner lining section comprising laterally and vertically aligned rows of independently supported relatively thin refractory panel units suspended thereon in spaced protective relation therewith, each of said units being fully and rigidly supported in an upright position in the lining by a single supporting member, and being capable of independent expansion in all directions to prohibit accumulative enlarged expansion of said lining section; said supporting member being a part of the furnace wall, being bonded and securely anchored therein, and extending inwardly from its inner side into contact with one said lining panel unit, said supporting member having on the inwardly extended portion, an integral elevated centrally located rib on its upper surface extending from the inner side of the furnace wall to the inner end of the supporting member, and having at its inner extended end at each side of said rib a lug integral therewith for supporting said lining panel unit thereon, and said rib being proportioned to act as a spacer means for suspending said panel units an even distance from said furnace wall.

7. A furnace wall according to preceding claim 6, in which the supporting member is provided with separate anchoring means adapted to mechanically interlock with said furnace wall.

8. A furnace wall according to preceding claim 6, in which said supporting member is provided with a channel at one end thereof for receiving a metallic anchor member adapted to interlock with said furnace wall.

9. A furnace wall according to preceding claim 6, in which the inner end surface of the supporting member is channeled to provide air passageways between said end surface and the outer surface of said lining panel unit for more efficient cooling thereof.

10. In a furnace wall comprising a fire side lining of the type described and illustrated herein, a panel filler brick seated upon and interlocked with another panel brick to complete the panel structure, said ller brick being of equal width with said other panel brick and having rabbeted edges for overlapping the edges of adjacent panel iiller bricks, said filler brick also having sealing lugs on its end edges adapted to fit into corresponding recesses in the end edges of adjacent panel tiller bricks.

11. A fire side lining according to preceding claim 10 in which the filler brick ismade to a height allowing suitable clearances between its upper surfaces and the adjacent panel above to permit disengagement from its interlocked position on the other panel brick and renewal in the lining from the tire side thereof, and resilient high temperature resistant packing material in the clearance exposed to the lire, said filler brick having at least the upper portion of its re face tilted at an upwardly and outwardly angle out of alignment with respect to the lire face of the other panel brick to form a slightly undercut lining section immediately below the bottom edge of each vertically succeeding panel, to prevent slag fIom flowing into the expansion joint therebetween.

References Cited in the le of this patent UNITED STATES PATENTS 1,489,683 Allen Apr. 8, 1924 1,639,138 Liptak Aug. 16, 1927 1,806,113 Nygaard May 19, 1931 1,812,315 Baumgartner .Tune 30, 1931 1,830,384 Crysler Nov. 3, 1931 1,944,569 Nygaard Jan. 23, 1934 1,957,820 Crysler May 8, 1934 1,992,620 Johnson Feb. 26, 1935 2,070,547 Grohn Feb. 9, 1937 2,084,225 Slaughter June l5, 1937 2,107,524 Crombie Feb. 8, 1938 

